由正弦定理可得:a/sinA = b/sinB ,则有:asinB = bsinA = 2 ;
因为,tanB = sinB/cosB = (asinB)/(acosB) = 5/2 ,
所以,B = arctan(5/2) .(题中应该是求B的度数,C的度数已知条件不足无法求出)
由正弦定理可得:a/sinA = b/sinB ,则有:asinB = bsinA = 2 ;
因为,tanB = sinB/cosB = (asinB)/(acosB) = 5/2 ,
所以,B = arctan(5/2) .(题中应该是求B的度数,C的度数已知条件不足无法求出)